In 1990, a clandestine mass grave with 1.049 unidentified mortal remains was found at the Dom Bosco Cemetery located in Perus, a suburban district of the city of São Paulo. It represents one of the innumerous crimes committed by the Brazilian dictatorial regime, which emerged with the military coup d’état in 1964 and lasted until 1985. The discovery of the Vala Clandestina de Perus (Perus illegal ditch), as it came to be known, was possible due to the courage and perseverance of a few individual persons.